Ophthalmic lens



Patented Got. 20, 1925..

UNITE. fi'lATEaii l.,tilif,63l PATENT OFFICE.

EDGAR D. TILLYER, C1 SOUTI-IBRIDGE, IJTASSAUHUSETTS. AESIGNOB T0 AMERICAN OPTICAL OOIVIPAIIY, OF SOUTHBRIDGE, CJUSETTS, A VOLUNTARY ASSOCIA- TION 0F ItIASSAGHUSETTfi.

OPHTHALMIC LENS.

1T0 Drawing".

To all whom it may concern:

Be it known that I, Eowann I). Trtnrnn, a citizen of the United States, residing at Southbridge, in the county of VVorce'ster and State of Massachusetts, have invented certain new and useful Improvements in Ophthalmic Lenses, of which the following is a specification.

This invention relates to improvements in ophthalmic lenses, and has particular reference to a novel and improved commer: cial ophthalmic lens and to the art or process of producing the said article.

Ophthalmic lenses at the present day are of many different grades and types, depending on the manufacturer producing the same, the accuracy and processes of manufacture, and the particular type of lens involved. At the present time there are marketed certain ophthalmic lenses of very high grade and expensive type resulting from the use of the highest possible grade of workmanship, material and equipment, while at the same time there are also on the market numerous imitations of a much inferior quality. As an ophthalmic lens is a structure designed to be placed on the face and employed for visual purposes, it has hitherto been found impossible to so mark or designate the lens that the purchaser could be sure of the grade and quality of product, the name of the manufacturer. or the like, since any such designations, if applied to the lens, would be either temporary and liable to be removed during the necessary cleaning before delivery of the lens to the patient, or, if attempted to be permanently applied, would be of a visible character tending to interfere with vision or with the appearance of the mounting so as to cause the same to be refused by the purchaser.

It is. therefore, one of the principal ob jects of the present invention to provide as a novel article of manufacture, a lens which shall be provided with a permanent mark or designation, that is to say, a designation which will not be removed or impaired by the ordinary cleaning to which lenses are subjected and yet which will be invisible under ordinary service conditions.

A further object of the invention is the provision of a novel and improved art or process of producing these designations on 18118. i i

Serial No. 558,758.

In the carrying out of my invention I first construct a lens from ordinary crown or flmt glass, or a suitable combination of both, surfacing it in the usual manner on either one ferred.

After the lens has been finally finished on at least one surface it is in condition for the carrying out of our process, whichconsists in applying to the finished surface of the lens, either by pen, brush, rubber stamp, stencil, Or other desired manner, suit-able designations, such as the trade-mark, name of the manufacturer, or the like. While I have found that several different substances may be employed for this purpose, I would give as an example of one which I have found quite satisfactory, phosphoric acid. The acid having been applied. to the lens surface and left there a predetermined period, I may then, if desired, directly remove the acid, which as is known is of what is known as non-drying type, that is, it will not dry off under ordinary climatic conditions, this removal being done as by washing to prevent undue spreading of the acid over the surface of the lens during removal exceptin very dilute form.

While as stated I may directly wash off the acid, I have found that it is preferably or both.- faces as may be preafter its application to subject the lens to a heating action which will aid in the result to be accomplished. This result consists in changing the hydroscopic properties of the surface of the lens or modifying its surface tension. The purpose of this modification of the surface of the glass to this extent resides in the fact that this surface modi fication is not an eating into or destroying of the polish of the surface of the glass which is visible under ordinary conditions, but is one which will affect the physical or chemical condition of the surface in such manner that upon subjecting the same to slight moisture, such as the moisture of the breath when blowing upon the glass, the

diflerence in surface will cause the moisture, as is usual, to condense in globules but the condensated globules on the modified part which has been treated by the acid will be different as to size from those on the re niainder of the lens, with the result that light striking the surface will be differently affected. so that the letters, words, or the like, will clearly stand out as distinct from the remainder of the lens and may be readily observed so long as the surface moisture endures but will entirely disappear as the lens surface dries off.

I have found by the production of these lenses that they may be subjected to indefinite washing, Wiping, or other cleaning actions, without impairing the'visibility of the designation marks. I refer to the use of phosphoric acid as particularly desirable in this connection since I have found this is one of the substances which will tend to add to the glass surface rather than to subtract therefrom, that is to say, there is no modification of the surface perceptible in any ordinary manner yet clearly perceptible under the hydroscopic test, but the action i is apparently a changing of the glass at these points to what is known as phosphoric glass, a recognized form of glass in the industries, having much greater hydroscopic properties than do more common forms of glass, such as employed in the manufacture of spectacle lenses.

I claim:

1. An ophthalmic lens having a polished refracting lens surface and a spot 'onsaid surface having a different reaction to vapor than the rest of the surface, and being without refractive effect on the lens surface in the absence of vapor.

2. An ophthalmic lens having anon-phosphoric body portion having a polished refracting lens surface thereon, and a spot of phosphoric glass on the refracting surface, said spot being Without refractive effect on the lens surface in the absence of vapor and having a different reaction to vapor than the non-phosphoric portion.

EDGAR D. TILLYER. 

